摘要
目的 探讨一例表面抗原阴性的隐源性肝硬化的病原及其分子基础。方法 定性、定量测定患者血清中的乙型肝炎病毒 (HBV)抗原、抗体和DNA ,进行HBVS基因的扩增、克隆和序列分析。结果 HBsAg (- ) ,定量测定结果 (S/N) :0 77(阳性参考值S/N≥ 2 0 0 )。HBeAg (+) ,定量测定结果 (S/N) :5 6 4 3(阳性参考值≥ 2 10 )。抗 HBc (+) ,定量测定结果 (S/CO) :0 0 3(阳性参考值S/CO≤1 0 )。抗 HBs (+) ,抗 HBe (- ) ,HBVDNA (+) ,定量 :1 5 4× 10 9拷贝 /ml。S基因克隆和序列分析发现第 336位核苷酸由C变为A ,导致第 6 1位密码子由UCA(丝氨酸 )变为UAA(终止子 ) ,HBsAg合成受阻。结论 HBV是本例肝硬化的病原 ,S基因终止突变是其分子基础 ,这一发现具有重要的临床意义和病毒学意义。
Objective To explore the pathogen and molecular basis of cryptogenic cirrhosis in a patient. Methods Serum was collected from a patient, male, aged 56, with cryptogenic cirrhosis. HBV serologic markers were qualitatively tested, and HBsAg, HBeAg, and anti HBc were quantitatively determined again. HBV DNA in serum was qualitatively tested using PCR, and quantified using fluorescence quantitative PCR. S gene was amplified, cloned, and sequenced. Results HbsAg and anti Hbe were negative, and anti HBs, HBeAg, anti HBc, and HBV DNA were all poaitive. HBsAg (S/N) was 0 77(cutoff of S/N:≥2 00), HbeAg (S/N) was 56 43 (cutoff of S/N:≥2 10), anti HBc (S/C O) was 0 03 (cutoff of S/C O:≤1 00); HBV DNA was 1 54×10 9 copies/ml. An uncommon point mutation at nucleotide 336 (C to A) in S gene was found, resulting in the change of the 61st codon into a novel stop codon and failure of synthesis of HbsAg. Conclusion HBV proves the pathogen of this case. This special mutation well explains the patient′s unusual serologic pattern. Moreover, this finding possesses important clinical and theoretical significance.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2002年第6期400-402,共3页
National Medical Journal of China
